NF EN ISO 5136
Acoustics - Determination of sound power radiated into a duct by fans and other air-moving devices - In-duct method
ISO 5136 specifies a method for testing ducted fans and other air-moving devices to determine the sound power radiated into an anechoically terminated duct on the inlet and/or outlet side of the equipment. The method is applicable to fans which emit steady, broad-band, narrow-band and discrete-frequency sound and to air temperatures between - 50 °C and + 70 °C. The test duct diameter range is from 0,15 m to 2 m. Test methods for small (d < 0,15 m) and large (d > 2 m) test ducts are described in the informative annexes H and I, respectively. The maximum mean flow velocity at the microphone head for which the method is suitable, depends on the type of microphone shield used, and is as follows: foam ball 15 m/s; nose cone 20 m/s; sampling tube 40 m/s. Above these values the suppression of turbulent pressure fluctuations by the microphone shield may be insufficient. The method described in ISO 5136 is applicable to a sound source in which a fan is connected to ducts on at least one side. It is also applicable to other fan/attenuator combinations or equipment incorporating fans which can be considered as "black boxes". Examples of fans and other equipment covered by ISO 5136 are ducted centrifugal fans, ducted axial flow fans, ducted mixed-flow fans, ducted air-handling units, ducted dust-collection units, ducted air-conditioning units, and ducted furnaces. ISO 5136 is also applicable to other aerodynamic sources such as boxes, dampers and throttle devices provided that a quiet air flow delivered by an auxiliary fan is available, and the signal-to-noise ratio of sound pressures to turbulent pressure fluctuations in the test duct is at least 6 dB. It is not applicable to non-ducted fans or equipment.
ISO 5136 specifies a method for testing ducted fans and other air-moving devices to determine the sound power radiated into an anechoically terminated duct on the inlet and/or outlet side of the equipment.
The method is applicable to fans which emit steady, broad-band, narrow-band and discrete-frequency sound and to air temperatures between - 50 °C and + 70 °C. The test duct diameter range is from 0,15 m to 2 m. Test methods for small (d < 0,15 m) and large (d > 2 m) test ducts are described in the informative annexes H and I, respectively.
The maximum mean flow velocity at the microphone head for which the method is suitable, depends on the type of microphone shield used, and is as follows:
foam ball 15 m/s; nose cone 20 m/s; sampling tube 40 m/s.
Above these values the suppression of turbulent pressure fluctuations by the microphone shield may be insufficient.
The method described in ISO 5136 is applicable to a sound source in which a fan is connected to ducts on at least one side. It is also applicable to other fan/attenuator combinations or equipment incorporating fans which can be considered as "black boxes".
Examples of fans and other equipment covered by ISO 5136 are
ducted centrifugal fans, ducted axial flow fans, ducted mixed-flow fans, ducted air-handling units, ducted dust-collection units, ducted air-conditioning units, and ducted furnaces.
ISO 5136 is also applicable to other aerodynamic sources such as boxes, dampers and throttle devices provided that a quiet air flow delivered by an auxiliary fan is available, and the signal-to-noise ratio of sound pressures to turbulent pressure fluctuations in the test duct is at least 6 dB.
It is not applicable to non-ducted fans or equipment.
<div id="MathJax_Message" style="display: none;"></div> <p>ISO 5136 specifies a method for testing ducted fans and other air-moving devices to determine the sound power radiated into an anechoically terminated duct on the inlet and/or outlet side of the equipment.</p> <p>The method is applicable to fans which emit steady, broad-band, narrow-band and discrete-frequency sound and to air temperatures between - 50 °C and + 70 °C. The test duct diameter range is from 0,15 m to 2 m. Test methods for small (<em>d </em>< 0,15 m) and large (<em>d </em>> 2 m) test ducts are described in the informative annexes H and I, respectively.</p> <p>The maximum mean flow velocity at the microphone head for which the method is suitable, depends on the type of microphone shield used, and is as follows:</p> <p>foam ball 15 m/s; nose cone 20 m/s; sampling tube 40 m/s.</p> <p>Above these values the suppression of turbulent pressure fluctuations by the microphone shield may be insufficient.</p> <p>The method described in ISO 5136 is applicable to a sound source in which a fan is connected to ducts on at least one side. It is also applicable to other fan/attenuator combinations or equipment incorporating fans which can be considered as "black boxes".</p> <p>Examples of fans and other equipment covered by ISO 5136 are</p> <p>ducted centrifugal fans, ducted axial flow fans, ducted mixed-flow fans, ducted air-handling units, ducted dust-collection units, ducted air-conditioning units, and ducted furnaces.</p> <p>ISO 5136 is also applicable to other aerodynamic sources such as boxes, dampers and throttle devices provided that a quiet air flow delivered by an auxiliary fan is available, and the signal-to-noise ratio of sound pressures to turbulent pressure fluctuations in the test duct is at least 6 dB.</p> <p>It is not applicable to non-ducted fans or equipment.</p>
- Avant-proposiv
- Introductionv
-
1 Domaine d'application1
-
1.1 Généralités1
-
1.2 Type de source de bruit1
-
2 Références normatives2
-
3 Termes, définitions et symboles3
-
4 Exactitude de la méthode de mesurage7
-
5 Dispositifs d'essai et instrumentation9
-
5.1 Exigences générales9
-
5.2 Spécifications relatives aux conduits10
-
5.3 Instrumentation16
-
5.4 Calibrage21
-
6 Installation d'essai21
-
6.1 Montage de la sonde microphonique21
-
6.2 Position du microphone21
-
6.3 Réglage du point de fonctionnement22
-
7 Mode opératoire23
-
7.1 Conditions de fonctionnement23
-
7.2 Mesurage des niveaux de pression acoustique23
-
7.3 Mesurages effectués avec et sans croisillon côté refoulement24
-
7.4 Mesurages côté aspiration - Gros ventilateurs: installation de catégorie D (selon l'ISO 5801:1997)24
-
8 Calculs24
-
8.1 Niveau de la pression acoustique moyenne24
-
8.2 Niveau de puissance acoustique25
-
9 Informations à consigner25
-
10 Informations à rapporter26
- Annexe A (normative) Détermination de la correction combinée vitesse moyenne d'écoulement/correction modale C3,427
- Annexe B (normative) Détermination du rapport signal-bruit des fluctuations de pression acoustique sur les fluctuations de pression turbulente dans le conduit de mesurage33
- Annexe C (normative) Méthodes de calcul du niveau de puissance acoustique pondéré A à partir des niveaux de puissance acoustique par bande de tiers d'octave36
- Annexe D (informative) Exemple de calcul de C3,4 pour un diamètre de conduit et une vitesse moyenne d'écoulement donnés37
- Annexe E (informative) Directives pour l'étude et la réalisation d'une terminaison anéchoïque40
- Annexe F (informative) Évaluation des caractéristiques des terminaisons anéchoïques49
- Annexe G (informative) Exemple de sonde microphonique52
- Annexe H (informative) Méthode d'essai pour les ventilateurs en conduit de taille réduite56
- Annexe I (informative) Méthode d'essai pour les ventilateurs en conduit de grande taille60
- Annexe J (informative) Mesurage de l'élément de giration67
- Bibliographie68
The Requirements department helps you quickly locate within the normative text:
- mandatory clauses to satisfy,
- non-essential but useful clauses to know, such as permissions and recommendations.
The identification of these types of clauses is based on the document “ISO / IEC Directives, Part 2 - Principles and rules of structure and drafting of ISO documents ”as well as on a constantly enriched list of verbal forms.
With Requirements, quickly access the main part of the normative text!
COBAZ is the simple and effective solution to meet the normative needs related to your activity, in France and abroad.
Available by subscription, CObaz is THE modular solution to compose according to your needs today and tomorrow. Quickly discover CObaz!
Request your free, no-obligation live demo
I discover COBAZ